Put the fisher calibrator tube on the test base, pay attention to the upside, turn clockwise to compact the powder, now the manometer crescent level rises, when the level become still, which could take about 2 minutes, turn the rack and pinion control to make the manometer level pointer coincides the crescent water level, now the value the size pointer show should be the high value on the fisher calibrator tube, if it is not, repeatedly turn the high need valve. During rotation, make the exhausting bubble in the regulator at rate of about 2 to 3 pcs per second.